Regenerative gas combustion furnace for liquid fuels



July 10 1951 A. Nn-:LsEN 2,559,729

REGENERATIVE GAS COMBUSTION FURNACE FOR LIQUID FUELS 43 v 20 e/ fz f E 3 /4 v fa' d 2,559,729 REGENERATIVE GAS CoMBUsTIoN FURNACE FoR LIQUID FUELS Filed Feb. 11,l 1948 A.' Nn-:LsEN

3 ShebS-Sheet 2 S NvEN-ro @mmh July 10, 1951 A. NlELsEN 2,559,729

REGENERATIVE GAS COIVBUS'IION FURNACE F OR LIQUID FUELS Filed Feb. 11, 194s 3 sheets-sheet s Awrnd Nl-elsen \N VE N To@ the burner.

Patented July 10, 1951 UNITED STATES PATENT OFFICE REGENERATIVE GAS COMBUSTION FURNACE FOR LIQUID FUELS Alfred Nielsen, Soro, Denmark, assignor to Universal Oilgas Heating A/S, Copenhagen, Denmark, a corporation of Denmark Application February 11, 1948, Serial No. 7,581 In Great Britain February 19, 1947 a thorough mixing and a practically homogeneous mixture of the oil gas and the air so as to afford a perfect combustion and a good economy of operation.

Another object is to provide an oil gas burner in which the oil gas and the air are caused to now through a suitably heated channel or duct, before being ignited, so as to intensify their mixing by diffusion.

A further object is to provide an oil gas burner constituting a self-contained unit which may be mounted at the front of a boiler or the like to heat the same.

Still another object is to provide an oil gas burner which is of a simple and inexpensive construction and reliable in operation.

With these and other objects in View the invention comprises the combination of parts described in detail hereinafter and specifically set forth in the appended claims.

Reference will now be had to the accompanying drawing in which Fig. 1 is a sectional elevation of a preferred form of an oil gas burner in accordance With the invention,

Fig. 2 is a section taken along the line II-II in Fig. 1,

Fig. 3 is a sectional view, taken along the line III-III in Fig. 1,

Fig. 4 is a detail sectional view at an enlarged scale, taken along the line IV-IV in Fig. 2, and

Fig. 5 shows an assembly of the oil gas burner.

In the drawing, I is the base portion of a housing enclosing the burner. The base portion I is secured, as by means of bolts 2, to the front plate 3 of a boiler or the like to be heated by means of The housing member I is provided with a refractory lining 4 constituting the walls or parietal elements of a combustion chamber 5 which latter opens into the boiler furnace through a flanged outlet aperture 6 in the front plate thereof. The wall of the combustion chamber 5 constitutes a partition which denes upper and lower portions in said housing and is provided with a circular opening I adapted to receive, with a certain annular gap clearance, the bottom of a cylindrical vaporizer or vessel 8 in which the fuel is vaporized. The vessel 8, which is open at its supply pipe 2l.

upper end, is by means of a ange 9 bolted to the loWer side of an annular pan I0, the inner cylindrical wall II of which is flush with the cylindrical wall of the vessel 8. The assembly constituted by the vaporizer or vessel 8 and the pan I0 is supported by a cylindrical housing member or jacket I 2 bolted to the upper side of the housing member I, in such a manner that the bottom of the vaporizer or vessel 8 is substantially flush with the ceiling of the combustion chamber 5.

The annular pan II] is provided with a cover I3 closing the pan as well as the vaporizer or vessel 8.

The annular space of the pan I0, which is denoted by I4, constitutes part of a mixing duct or channel. A transverse partition I 5 is provided at the side of the pan I0 remote from the boiler, which partition bends one end of the duct or channel I4 through a soft curve into a radially directed aperture I6 in the outer cylindrical wall of the pan IU. This aperture opens into one end of a semi-circularly curved by-pass channel or duct I'I which, at its other end, opens as an inlet into the rear end of the combustion chamber 5. The rectangular cross section of the by-pass channel or duct I'I is gradually increasing from the upper to the lower end thereof (see Figures 1 3) so as to constitute a gradual transition from the channel I4 tothe wider section of the combustion chamber 5. At the joint between the .by-pass channel or duct I'I and the combustion chamber 5 there is inserted a transverse wall I8 of wire gauze for preventing the burner ame from blowing back into the mixing channel I4, I'I.

At the end of the channel I4 remote from the outlet IB, there is provided an aperture I9 in the wall II which constitutes communication between the interior of the Vessel 8 of which it is the outlet and the channel I4. An air supply or inlet pipe 2u is introduced through the outer wall of the pan Il! radially opposite. the aperture I9, but at a higher level than the latter (see Fig. 4). An oil supply pipe 2l extends into the vaporizer or vessel 8 near the bottom thereof. The air supply pipe 20 is connected with the delivery side of a fan blower 22 which is driven by means of an electro-motor 23. The motor 23 also drives a fuel pump 24, which may be a gear pump and which is connected with the fuel Since the normal fuel consumption is only a fraction of the capacity of the pump, a return line 25 is branched oi from the supply 1o-ipe 2i for returning the surplus fuel to the fuel tank. This return line is provided with a spring-loaded non-return valve 26 for insur- 3 ing a certain counter-pressure in the branch line 25 which will be suicient to raise the oil in the supply pipe 2I to the level of the upper end of this pipe. The supply pipe 2I is provided with a regulating valve 2, such as a needle valve, which is mechanically connected with a swivel damper 28 in the air supply pipe 20 in .such a manner that, by rotation of the common spindle 29 of the valve 2l and the damper 28, both supply p-ipes 20 and 2I are either throttled down or opened simultaneously. For automatically effecting this control a thermostat 3B of some convenient type is mounted on the boiler front and is by means of a chain or rod 3| connected with a lever 32 secured to the spindle 29 for adjusting the members 2, 28 in accordance with the temperature of the boiler. The valve 2l and the damper 28 may be so trimmed that, during normal conditions of operation of the fan 22 and the pump 24, an adequate mixture of oil gas -f and air is obtained at any position of the spindle 29. This trimming may to some extent be effected by means of a separate trimming damper 35 in the air supply pipe 20 which is adapted to lue-adjusted by means of a screw 3ft.

In operation, oil or other liquid fuel is supplied through the pipe 2| to the vaporizer or vessel 8, which is heated by the burner flame. When coming into contact With the hot Walls of the vessel, the oil Will be instantly vaporized and the vapors will flow through the aperture I9 into the annular duct or channel Id. to which air is supplied from the fan 22 through the pipe ZIE. The ow of air and oil gases entering the channel Afrom opposite sides thereof, a slight turbulence will occur at the inlet end of the channel I4, as indicated in Fig. 4. The channel is however, so widely dimensioned that the mixture will subsequently now quietly and substantially without Whirls through the soft curves of the ducts or channels I4 and Il, to the combustion chamber A5 in which combustion of the mixture takes place. Some of the heat generated by this Vcombustion is allowed to escape through the annular gap between the bottom of the vessel k8 and the edge of the opening I to the interior of the housing member or jacket I2 enclosing the pan I8. Therefore, the Walls of the channel I4 will be heated to such an extent as to prevent condensation of the oil gases thereon. On the other hand, the temperature of the Walls of the .channel I4 will not be such as to involve danger Aforming a jacket 36.

The vaporization of oil in the vaporizer 8 will cause a layer of carbon to be deposited therein. Such deposits may, however, be easily removed when the cover I3 is removed. Carbon deposits in the aperture I9, if any, may be removed by means of -a cleaning device comprising a rod 31 mounted in a bore in the outer Wall of the pan Ill vfor sliding movement in axial alignment with the aperture I9. The end of the rod projecting 'from the housing I2 is provided with a knob 38 serving as a handle, and the inner end of the rod is formed with a head 39 of a slightly smaller diameter than the aperture I9. It will be appreciated that, when the rod 3l is actuated, any carbon deposits in the aperture I9 will be pushed into the vessel 8. A spring ci) is provided for automatically retracting the rod from the aperture I9.

When the burner is cold and is to be started, the vessel or vaporizer 8 must be initially heated. This initial heating may be effected by any convenient means, such as a gas burner, an electric heating member, or the like. In the example shown, the preliminary heating is eiected by burning oil in a small receptacle 4I arranged at the bottom of the housing I, I2 'beneath an aperture 2 in the bottom of the combustion chamber 5. The receptacle is connected with a pipe 43 which is branched on" from the fuel supply pipe 2i and which can be closed by means of a valve 44, and is also connected with the blast pipe 20 through the medium of a branch pipe 45 therefrom including a manually operable damper 4S.

For starting the burner, the motor 23 is started and the valve 2l and the damper 28 are closed, While the valve ifi and the damper "i6 are opened. Hereby oil and air are supplied to the receptacle 6I. A torch is now introduced through an aperture 4l in the Wall of the receptacle which is normally closed by means of a hinged ap 48. The oil Will thus be caused to burn sufhciently intensely to heat the bottom of the vessel or vaporizer 8. After a While the valve 2'! and the I damper 28 are opened so that the normal operation of the burner commences, the gas mixture formed in the mixing duct or channel I4, I'I being ignited by the flame from the burning oil in the receptacle 4I. Finally the valve 44 and the damper 46 are closed, whereby the combustion in the receptacle @i is choked.

What I claim is:

l. An oil gas burner, comprising a housing, a combustion chamber Within said housing, the upper Wall of said chamber defining a partition between the upper and lower portions of said burner, the lower portion constituting the combustion chamber, an outlet from said combustion chamber at one end thereof, an inlet at the opposite end thereof, said partition having an opening therein, a vaporizer mounted in said `upper portion and extending into said opening to be exposed to heat in said combustion chamber, said opening and said vaporizer being so dimensioned as to form an annular gap between them to constitute communication between said combustion chamber and said upper portion, an outlet from said vaporizer, a duct extending substantially annularly around said vaporizer within said upper portion from said last-named outlet to the inlet of said combustion chamber, and an air inlet in said duct adjacent the outlet from said vaporizer.

2. An oil gas burner, comprising a housing, a combustion chamber Within said housing, the upper Wall of said chamber dening a partition between the upper and lower portions of said burner, the lower portion constituting the combustion chamber, an outlet from said combustion chamber at one side of said housing, an inlet to said combustion chamber at the opposite side of said housing, a duct extending from said inlet to said upper portion, a vaporizer exposed to heat in said combustion chamber, and disposed substantially centrally in said upperV portion, an

outlet from said vaporizer, a duct extending substantially annularly around said vaporizer within said upper portion from said last-named outlet to the upper end of said duct connected with the inlet of said combustion chamber, an air inlet in said annular duct adjacent said outlet, and an opening in said partition to constitute communication between said combustion chamber and said upper portion.

3. An oil gas burner as in claim 2, in Which said duct connected with the inlet of said combustion chamber extends outside said housing and is provided with a heat-insulating layer.

4. An oil gas burner, comprising a housing, a combustion chamber within said housing, the upper wall of said chamber defining a partition between the upper and lower portions of said burner, the lower portion constituting the combustion chamber, an outlet from said combustion chamber at one side of said housing, an inlet to said combustion chamber at the opposite side of said housing, a duct extending from said inlet to said upper portion, a substantially cylindrical vaporizer disposed substantially centrally in said upper portion and extending through said partition to have its bottom exposed in said combustion chamber, an outlet from said vaporizer at the upper end thereof, a channel extending substantially annularly around said vaporizer within said upper portion from said last-named outlet to the upper end of said duct connected with the inlet of said combustion chamber, an air inlet in said channel adjacent said outlet, a removable cover closing the top end of said vaporizer and the upper side of said channel, said f partition having an opening in the upper portion thereof to establish communication between said combustion chamber and said upper portion.

5. An oil gas burner, comprising a housing, a combustion chamber within said housing, the upper wall of said chamber defining a partition between the upper and lower portions of said burner, the lower portion constituting the combustion chamber, an outlet from said combustion chamber at one end thereof, an inlet at the opposite end thereof, a vaporizer disposed substantially within said upper portion and extending through said partition to have its bottom exposed in said combustion chamber, said bottom being substantially ush with the lower side of said partition, an outlet from said vaporizer, a duct extending substantially within said upper portion from said last-named outlet to said inlet, an air inlet in said duct adjacent the outlet from said vaporizer, said partition having an opening therein to establish communication between said combustion chamber and said upper portion.

6. A regenerative oil gas burner, comprising a vaporizer, parietal means defining a combustion chamber, said Vaporizer being exposed to the heat within said combustion chamber, an outlet from said vaporizer, an inlet to said combustion chamber and an outlet therefrom, a relatively elongated duct connecting said first-named vaporizer outlet with said inlet, an air inlet in said duct adjacent said rst-named outlet, a jacket spaced from and substantially completely enclosing said vaporizer, and means provided with communicating passageways between said combustion chamber, and the interior of said jacket, whereby to permit a portion of the hot gases generated in said combustion chamber to enter said jacket, so as to heat said duct and thereby to maintain the contents thereof in the Vapor phase.

7. An oil gas burner, comprising a vaporizer, parietal means defining a combustion chamber. said vaporizer being exposed to heat present in said combustion chamber, an outlet from said vaporizer, an inlet to said combustion chamber and an outlet therefrom, a duct connecting saidv rst named outlet with said inlet, an air inlet in said duct adjacent said rst named outlet, a jacket spaced from and substantially completely enclosing said vaporizer, an outlet from said jacket, and means affording communication for heated gases between said combustion chamber and the interior of said jacket, so as to permit part of the hot gases generated in said combustion chamber to flow through said jacket an through said outlet therefrom. Y

8. A regenerative oil gas burner, comprising a housing, walls dening a combustion chamber in the lower portion of said housing and having an outlet near the bottom thereof, a Vaporizer mounted in the upper portion of said housing, lying above and exposed to the heated gases rising from said combustion chamber, an inlet at the end of said combustion chamber opposite said outlet, an outlet from said vaporizer at the upper end thereof, a duct situated substantially within the upper portion of said housing and extending between said outlet from said vaporizer and said inlet to said combustion chamber, and an air inlet in said duct adjacent said outlet from said vaporizer.

9. An oil gas burner, comprising a housing, a combustion chamber within said housing, the upper wall of the chamber dening a partition between the upper and lower portions of said burner, the lower portion constituting the combustion chamber, an outlet from said combustion chamber at one end thereof, an inlet at the opposite end thereof, a Vaporizer exposed to heat in said combustion chamber, an outlet from said vaporizer, a duct in the upper portion extending substantially from said last named out, let to said inlet, an air inlet in said duct adjacent the outlet from said vaporizer, said partition having an opening to establish communication between said combustion chamber and said upper portion.

ALFRED NIELSEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 757,395 Falkenwalde Apr. 12, 1904 811,429 McKnight Jan. 30, 1906 1,048,310 Hemphill et al. Dec. 24, 1912 1,577,815 Snowden Mar. 23, 1926 1,684,990 Inglis Sept. 18, 1928 2,128,171 Tullis Aug. 23, 1938 2,373,492 Nelson et al. Apr. 10, 1945 2,445,302 Clarkson July 13, 1948 

